Mayor de Blasio marks the 150th anniversary of the FDNY, which was founded in 1865.

The FDNY celebrated its 150th anniversary Monday with the unveiling of a plaque in Midtown commemorating the “heroism of New York’s Bravest.”

About 100 people — half of them uniformed smoke-eaters — were on hand for the ceremony at the Emigrant Savings Bank at 6 E. 43rd St. The bank is also home to the “Kneeling Fireman” statue, which served as a makeshift memorial in the weeks after 9/11.

The plaque’s inscription reads: “The selfless heroism of New York’s Bravest is a shining example of the best enduring qualities of Americans.”